A/D converter for load cells

We are looking for someone to desing an A/D Converter with four inputs Using the ADS1216 and the Attiny2313. The A/D converter must have 4 analog inputs 0 - 60 mV, 8 digital outputs TTL and 8 digital inputs TTL. and 1 interface RS485. The designer must provide Schematics, Files for PCB production and the source code of the software.